tools: imx8image: Fix the value passed to dcd_skip of build_container()

tools: imx8image: Fix the value passed to dcd_skip of build_container()

The value passed to dcd_skip of build_container() should be obtained by
parsing .cfg file, and should not be fixed to false. For i.MX8QXP, dcd
data needs to be skipped, in which case dcd_skip should be true.

Fixes: 5f28a6599f01("tools: imx8image: add i.MX95 support")

Signed-off-by: Alice Guo <alice.guo@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reported-by: Enric Balletbo i Serra <eballetb@redhat.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>